Apparatus for generating sonic and ultra-sonic vibrations in fluids

ABSTRACT

An apparatus is provided for producing oscillations in a fluid and the apparatus comprises a plurality of vibration generators arranged in sequence one after the next. Each generator has an annular casing with inlet ports for the introduction of fluid and an outlet port for discharge of fluid. At least two nozzles are mounted in each casing and are constituted by identical spiral shape screens uniformly arranged around the outlet port, adjacent portions of the screens overlapping each other by less than a central angle of 90*. The portions of the screens between the nozzles serve as deflecting blades which define an acute angle with each of the nozzles at the point of intersection of the streams fed from the nozzles. A common housing is provided for the generator casings and the inlet ports are separately fed with fluid, the outlet ports of the individual casings being coaxially arranged to combine the flow from the outlet of the generators in succession and cause the fluid to flow coaxially through the housing to a discharge outlet thereof.

Unite StatesPatent 1 Nekrasov et a1.

45 May 8, 1973 154] APPARATUS FOR GENERATING SONIC AND ULTRA-SONIC VIBRATIONS IN FLUIDS Alexei- Alexandrovich Sergeiehev,

ulitsa Tsyolkouskogo, l0, kv. 28,

both of Syzran, all of U.S.S.R. 22 Filed: Oct. 23, 1970 [21] App1.No.: 83,678

Related US. Application Data [62] Division of Ser. No. 752, 272, Aug. 13, 1968, Pat.

[52] US. Cl. ..239/l02, 239/266, 239/403, I 239/427.3, 239/472, 259/D1G. 43

[51] Int. Cl....- ...B05b 3/14, B05b 7/04, B05b 1/34 [58] Field of Search ..239/4, 102, 266, 239/267, 399, 400, 402, 403, 404, 406, 427,

624.14; 259/D1G. 43, DIG. 44

[56] References Cited UNITED STATES PATENTS 850,216 4/1907 Dornfeld ..239/486 3,182,916 5/1965 Schulz ..239/468 2,139,736 12/1938 Durham 137/315 3,056,590 10/1962 Harris ..259/Dig.44 1,769,046 7/1930 Walters et al ..239/486 X 2,791,468 5/1957 Grotta ..239/486 X FOREIGN PATENTS OR APPLICATIONS 237,372 4/1964 Austria ..239/468 229,404 l/19l0 Germany .....239/489 636,685 5/1950 Great Britain ..239/491 829,040 12/1951 Gennany ..239/l20 Primary Examiner-Robert S. Ward, Jr. Att0rneyWaters, Roditi, Schwartz & Nissen [57] ABSTRACT An apparatus is provided for producing oscillations in a fluid and the apparatus comprises a plurality of vibration generators arranged in sequence one after the next. Each generator has an annular casing with inlet ports for the introduction 01' fluid and an outlet port for discharge of fluid. At least two nozzles are mounted in each casing and are constituted by identical spiral shape screens uniformly arranged around the outlet port, adjacent portions of the screens overlapping each other by less than a central angle of 90. The portions of the screens between the nozzles serve as deflecting blades which define an acute angle with each of the nozzles at the point of intersection of the streams fed from the nozzles. A common housing is provided for the generator casings and the inlet ports are separately fed with fluid, the outlet ports of the individual casings being coaxially arranged to combine the flow from the outlet of the generators in succession and cause the fluid to flow coaxially through the housing to a discharge outlet thereof.

5 Claims, 6 Drawing Figures PATENTED MAY 75 SHEET 2 [IF 3 v bfm PATENTEUHAY 8197s SHEET 3 [1F 3 m at CROSS-RELATED APPLICATION This application is a division of application Ser. No. 752,272 filed Aug. 13, 1968 and issued as U.S. Pat. No. 3,614,961 On Oct.26, 1971.

This invention relates to ultrasonic vibration generatorsadapted for generating sonic and ultrasonic oscillations as well as to devices for carrying out this method.

One of the known methods of production of sonic and ultrasonic oscillations consists in continually introducing a flow of gas or fluid to impinge on diaphragms or on plates and rods mounted so as to be free to vibrate. 1 1

Interaction of the gas or fluid flow with the baffle (plate, rod or diaphragm) results in producing ultrasonic oscillations arising due to swirling action or pulsation of the flow. 7

When the flow pulsation frequency coincides with the natural vibration frequency of the baffle (plate, rod or diaphragm), it causes resonant oscillations of the baffle and the flow, which are then propagated into the adjoining medium.

Disadvantages inherent in this method of generating sonicand ultrasonic oscillations and in devices for carrying it into effect, are as follows: instability of the vibration frequency and power arising from alteration of the gas or fluid volumetric flow rate or from dimensional variations of the baffle (plate, rod, or diaphragm). These changes in the oscillation frequency, intensity, and power are due to pressure variations in the gas or fluid flow or to partial destruction (i.e., the dimensional variations) of the baffle by abrasive particles contained in the flow.

Another known method for the production of sonic and ultrasonic oscillations consists in forcing a gas flow into a hollow chamber (resonator) at an ultrasonic velocity. A disadvantage of this method is the impossibility to generate sonic and ultrasonic oscillations by utilizing the energy of a fluid flow, especially that of a combination of fluid and gas flows differing in their physical characteristics, since in this case the hollow chamber (resonator) should be of a very complicated design. 1

An object of the present invention is to avoid these disadvantages and to provide a method of generating ultrasonic vibrations, which ensures vibration frequency and power adjustment over relatively wide ranges due to the most efficient utilization of the gas or fluid When the two streams run against each other, they cause alternate retardation of each other at the baffle, which gives rise to pulsations of the stream at a definite repetition frequency at the place of retardation with a subsequent propagation of the arising ultrasonic vibrations through the reflected joint fluid or gas flow.

A device for carrying out the above method, i.e., a vibration generator, comprises at least two nozzles 0 mounted at an acute angle to each other, past which flow energy, and which also affords a simultaneous utilization of a fluid or gas and their suspensions and aerosols with solid matter as a vibrating medium, the dependence of sonic and ultrasonic vibrations upon dimensional variations of the resonators (plates, rods, diaphragms, and hollow chambers), being eliminated.

According to the invention said object is achieved by a method of generating oscillations in the sonic and ultrasonic frequency ranges by means of a flow of fluid or gas, which consists in continually introducing at least two streams running at an acute angle to each other to impringe on a baffle which deflects them, said baffle being fixedly mounted at the place where the two streams melt so that the joint flow is directed at an acute angle to each of the meeting streams.

nozzles a blade is provided, located at the point of meeting of the two streams of gas or fluid fed from said nozzles, so as to deflect said streams, said blade being inclined at an acute angle with each of the nozzles at the point of meeting of said streams.

According to the present invention, in a preferred embodiment of the vibration generator, this is expedient to have at least the nozzles formed by identical spiral screens uniformly arranged around a window provided in the generator bottom piece for the vibrating medium to discharge. The adjacent portions of these screens overlap each other by less than within the central angle, whereas the portions of each screen located between the nozzles serve as deflecting blades which are inclined at an acute angle with each of the nozzles at the points of meeting of the streams fed from said nozzles. 7

As to a vibration generator designed for transmitting oscillations to a medium which is not to be mixed with the fluid or gas streams fed to the generator, for imparting oscillations to the medium, which takes no part in producing the oscillations is mounted for expedience in front of the window for discharging the vibrating medium.

When vibration generators are used in a sonic or ultrasonic mixer for mixing liquid or gaseous fluids differing in physical characteristics, it is desirable to mount these generators in succession along the flow of the agents being mixed, which serve as vibrating media and have the same direction of circulation for all of said generators.

To atomize liquid in a gas or steam flow by utilizing sonic or ultrasonic oscillations for producing small and uniformly sized droplets of liquids or their suspensions with solid matter, it is expedient to arrange vibration generators in succession along the flow of the atomized liquid or liquids, the atomizing agent being fed to the last generator, the direction of the vibrating medium circulation for all the generators being the same.

When vibration generators are used in fuel burners in which besides the production of fine and uniformly sized droplets of the liquid fuel, there is a necessity to provide a uniform distribution of the atomized fuel throughout the entire torch volume as well as a high torch turbulization, it is expedient to mount at least three generators in succession along the dispersed fuel flow, so that the fuel is fed to the first generator, and a dispersing agent (steam, air, gas) is fed to the rest of them, the directions of circulation in the adjoining generators through which the dispersing agent is fed dispersing agent (air, steam), and with air-to-fuel ratio of 0.221 or the steam-to-water steam ratio of 0.1:1. The average and maximum droplet sizes are the same even when the fuel expenditure becomes 1.5 to 2 times as much as the normal one, with the expenditure of the dispersing agent (air, steam, gas) being constant. Moreover, the torch noise and the unit components vibration were insignificant due to the high frequency of the torch vibrations.

The accompanying drawing illustrates possible embodiments of I the vibration generator and devices designed for realizing the method provided by the present invention, wherein:

FIG. 1 is a schematic diagram illustrating the arrangementof the generator nozzles and wall involved in producing sonic and ultrasonic oscillations;

FIG. 2 .is a schematic diagram of the ultrasonic generator shown in an axonometric projection;

FIG. 3 is a central longitudinal section view of the ultrasonic generator for transmitting oscillations to a medium isolated from the internal cavity of the generator;

FIG. 4 shows a central longitudinal section view of the sonic (ultrasonic) mixer utilizing the vibration generator of the present invention;

FIG. 5 shows a central longitudinal section view of the sonic (ultrasonic) fluid sprayer utilizing the vibration generator of the present invention; and

FIG. 6 shows a central longitudinal section view of the ultrasonic liquid fuel burner utilizing the vibration generator of the present invention.

The principle of generating sonic and ultrasonic oscillations consists in the following. A fluid or gas flow is equally divided into two streams A and B'(FIG. l) which have identical characteristics such as .pressure, velocity, and flow rate, these two streams are directed through two identical nozzles I (having equal-area orifices) arranged at an acute angle (a) to each other. Being fed through the nozzles, these separated streams of fluid or gas meet at a deflecting blade 2 mounted fixedly at an acute angle (,8 and a respectively) to each of the streams, which are alternately retarded at the point of their meeting due to pressure increase in the fluid or gas streams in front of the outlets of nozzles 1.

The alternate and equally timed retardations of the streams meeting at the stationary baffle give rise to pulsation of the jointly reflected fluid or gas flow. The appearance of the rhythmic pulsations causes the generation of sonic or ultrasonic (which depends on the velocity of the streams) vibrations propagating over the reflected flow.

A sonic or ultrasonic vibration generator 3 (FIG. 2) has ports 4 provided in the walls of a chamber 5. A fluid or gas flow fed through these ports is uniformly distributed throughout the chamber and forced to the inlets of the nozzles 1 formed of identical arcuate positions or spiral screens 6 which are in effect the portions of the Archimedean spiral, uniformly arranged around a port 7 provided in a generator bottom 8 for the vibrating medium to discharge. The adjacent portions of the screens 6 overlap each other by less than 90 of the central angle, whereas the portions of each screen located between the nozzles serve as deflecting blades 2, which are inclined at acute angle with each of the nozzles at the points of meeting of the fluid or gas streams fed from said nozzles. While directed against each other at the blades, the streams are alternately retarded under the influence of centrifugal force and velocity, which causes rhythmic and alternate in time pulsation in these streams. The pulsating joint flow is expelled from the generator through the port 7.

When the vibration generator is used for transmitting oscillations to a medium (liquid or gas), which is for some reason not to be mixed with the fluid or gas flow involved in producing these sonic and ultrasonic oscillations,.there is to be mounted a diaphragm 9 (FIGS) in front of the generator port 7 for discharging a vibrating medium, said generator being fully discussed above in connection with FIG. 2.

To utilize the energy of sonic and ultrasonic oscillations for mixing and emulsifying liquids and or gases differing in their physical and chemical characteristics, a mixer 10 I (FIG. 4) incorporates three vibration generators 3a, 3b, 30, whose operating principle is comprehensively discussed above with reference to FIG. 2. These generators are mounted in succession along the flow of the mixing liquids and or gases pumped through pipes 11, l2, 13. The directions of circulation of the fluid or gas flows are identical for all the generators, involved, whereas the flows of the vibrating fluid or gas are discharged through the ports 7 in the bottoms of the generators to freely pass from one generator to another so as to get into the zones of the most intensive sonic and ultrasonic oscillations, wherein they are mixed and then forcedthrough a pipe 14 as a joint flow to be further utilized.

' It is a common knowledge that a droplet size, either for liquid or for mixture of liquids dispersed with the aid of some gas or steam, depends upon the amplitude and frequency of vibrations imparted to a dispersed liquid and to a dispersing gas. To utilize the effect of sonic and ultrasonic oscillations for dispersing liquid or liquids, a sprayer 15 (FIG. 5), is made for the purpose in accordance with the present invention, has three vibration generators 3d, 3e, 3f, which are discussed herein above with respect to FIG. 2, said generators being arranged in succession along the flow of the dispersed liquid, only the last generator 3f receiving gas for dispersion, the initial ones 3d, 3e being used for mixing only. The directions of the flow circulation for all the generators are identical, and the joint flow of the dispersed liquid and of the dispersing gas is issued through a profiled nozzle 16.

To provide highly dispersed and agitated flow of atomized fuel to be burnt up in an ultrasonic fuel burner 17 (FIG. 6) with the help of the energy of ultrasonic oscillations, use is made of three vibration generators 3g, 3h, 3k, which are discussed herein above with reference to FIG. 2, said generators being mounted in succession along the liquid fuel flow, the fuel being fed to the first generator, a dispersing agent to the rest of them. The directions of flow circulation in the adjoining generators through which the dispersing agent is fed are opposite to each other. The atomized fuel is fed into a furnace through a changeable profiled nozzle 18.

What is claimed is z 1. Apparatus for producing oscillations in a fluid comprising a plurality of vibration generators arranged in sequence one after the next, each said generator less than 90, the portions of said screens between said nozzles serving as deflecting blades which define an acute angle with each of said nozzles at the points of intersection of said streams fed from the nozzles to produce rythmic pulsations in the combined flows, and a common housing for the casings of said generators with means for feeding fluid to each of the inlet ports, the outlet ports being coaxially arranged such that the fluids flowing from the outlet of the generators combine in succession and flow coaxially through the housing, said housing having an outlet coaxially aligned with the outlets of the individual casings for discharge of the combined flows.

2. A vibration generator according to claim 1, in which a flexible diaphragm is mounted in front of said housing outlet for a vibrating medium to expel so as to transmit oscillations to an external medium which is not involved in producing said oscillations.

3. A mixer for gases or/and liquids using the vibration generators according to claim I, mounted in successionalong the flow of the agents being mixed, which serve at the same time as vibrating media having identical directions of circulation for all said vibration generators.

4. A liquid sprayer using the vibration generators according to claim I, mounted insuccession along the flow of the liquid or liquids, being atomized, a dispersing agent being fed to the last generator, the

directions of the vibrating media circulation being identical for all said vibration generators.

5. A fuel burner using at least three said vibration 

1. Apparatus for producing oscillations in a fluid comprising a plurality of vibration generators arranged in sequence one after the next, each said generator comprising: an annular casing including an upstanding wall member and top and bottom closure members, said casing having inlet ports for introduction of a fluid therein, and An outlet port in the bottom member for discharge of the fluid, at least two nozzles in said casing constituted by identical spiral-shape screens uniformly arranged around said outlet port, adjacent portions of said screens overlapping each other by a central angle less than 90*, the portions of said screens between said nozzles serving as deflecting blades which define an acute angle with each of said nozzles at the points of intersection of said streams fed from the nozzles to produce rythmic pulsations in the combined flows, and a common housing for the casings of said generators with means for feeding fluid to each of the inlet ports, the outlet ports being coaxially arranged such that the fluids flowing from the outlet of the generators combine in succession and flow coaxially through the housing, said housing having an outlet coaxially aligned with the outlets of the individual casings for discharge of the combined flows.
 2. A vibration generator according to claim 1, in which a flexible diaphragm is mounted in front of said housing outlet for a vibrating medium to expel so as to transmit oscillations to an external medium which is not involved in producing said oscillations.
 3. A mixer for gases or/and liquids using the vibration generators according to claim 1, mounted in succession along the flow of the agents being mixed, which serve at the same time as vibrating media having identical directions of circulation for all said vibration generators.
 4. A liquid sprayer using the vibration generators according to claim 1, mounted in succession along the flow of the liquid or liquids, being atomized, a dispersing agent being fed to the last generator, the directions of the vibrating media circulation being identical for all said vibration generators.
 5. A fuel burner using at least three said vibration generators according to claim 1, mounted in succession along the fuel flow, the fuel being fed to the first generator, a dispersing agent to the rest of them, the directions of circulation in the adjoining vibration generators, operating with the dispersing agent, being opposite. 